#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;

#define in read()
#define pii pair<int,int>
#define fi first
#define se second
#define FILE(x) freopen(x".in","r",stdin);\
	freopen(x".out","w",stdout);
#define pb push_back

int read(){
	int x = 0,sgn = 1;char ch = getchar();
	for(;!isdigit(ch);ch = getchar()) if(ch == '-') sgn = -1;
	for(;isdigit(ch);ch = getchar()) x = (x<<1)+(x<<3)+(ch^48);
	return x*sgn;
}

const int N = 210;
const int M = 3e4+10;
const int inf = 0x3f3f3f3f;

int id[N][2],d[N<<1],S,T,maxflow,now[N<<1],n,m,cnt = 1,h[N<<1],nodenum;
struct edge{int v,w,nxt;}e[M<<1];
void link(int x,int y,int w){e[++cnt] = (edge){y,w,h[x]};h[x] = cnt; e[++cnt] = (edge){x,0,h[y]};h[y] = cnt;}

bool bfs(){
	queue<int> q;q.push(S); memset(d,0,sizeof(d)); d[S] = 1; now[S] = h[S];
	while(q.size()){
		int x = q.front();q.pop();
		for(int i = h[x],y;i;i = e[i].nxt){
			if(!d[y = e[i].v] && e[i].w){
				d[y] = d[x] + 1; now[y] = h[y];
				q.push(y); if(y == T) return 1;
			}
		}
	}return 0;
}

int dfs(int x,int flow){
	if(x == T) return flow; int res = flow;
	for(int i = now[x],y;i&&res;i = e[i].nxt){
		now[x] = i;
		if(d[y = e[i].v] == d[x] + 1 && e[i].w){
			int k = dfs(y,min(res,e[i].w));
			if(!k) d[y] = 0; res -= k; e[i].w -= k; e[i^1].w += k;
		}
	}return flow - res;
}

int main (){
#ifndef ONLINE_JUDGE
	freopen("1.in","r",stdin);
#endif
	n = in,m = in;int a = in,b = in;
	for(int i = 1;i <= n;i++){
		id[i][0] = ++nodenum,id[i][1] = ++nodenum;
		int c = in; link(id[i][0],id[i][1],c);
	}
	for(int i = 1,u,v;i <= m;i++){u = in,v = in; link(id[u][1],id[v][0],inf);link(id[v][1],id[u][0],inf);}
	S = ++nodenum,T = ++nodenum; link(S,id[a][0],inf); link(id[b][1],T,inf);
	int flow = 0;
	while(bfs()) while(flow = dfs(S,inf)) maxflow += flow;
	bfs();
	for(int i = 1;i <= n;i++){if(!d[id[i][1]] && d[id[i][0]] || !d[id[i][0]] && d[id[i][1]]) printf("%d ",i);}
	return 0;
}

